A production problem

A production problem. A chair manufacturer makes three different types of chairs, each of which must go through sanding, staining, and varnishing. In addition, the model with the vinyl-covered back and seat must go through an upholstering process. The following table gives the time required for each operation on each type of chair, the available time for each operation in hours per month, and the profit per chair for each model. How many chairs of each type should be made to maximize the total profit? Model Sanding Staining Varnishing (hr) (hr) (hr) Upholstering Profit (hr) 1.0 0.5 0.7 0 10 1.2 0.5 0.7 0 13 A-solid back and seat B-ladder back, solid seat C-vinyl-covered back and seat Total time available per month 0.7 0.3 0.3 0.7 600 300 300 140